The term C-076 is used to describe a series of compounds isolated from the fermentation broth of a C-076 producing strain of Streptomyces avermitilis. The morphological characteristics of the culture are completely described in U.S. application Ser. No. 772,601, which is published as a German patent publication No. P27,170,407. The C-076 compounds are a series of macrolides each of which is substituted thereon at the 13-position with a 4-(.alpha.-L-oleandrosyl)-.alpha.-L-oleandrose group. The 2-series of C-076 compounds also has a 23-hydroxy group as well as several other hydroxy groups. The selective oxidation of the 23-hydroxy group, without affecting the remaining hydroxy groups is the subject matter of the instant application. The C-076 compounds and the instant derivatives thereof have a very high degree of anthelmintic and antiparasitic activity.